It showed the right rear tire low, then I got air put in it. I just bought the car so I haven't had the tires rotated yet. I was told to put on the emergency break, turn the ignition on ( but don't start it) on down the door lock/unlock on my key holder. The horn honked twice, then it displayed "Tire Relearning". I didn't know what to do after that.

Ah. Well to do a tire relearn after getting the "Tire Relearning" message you need to go to the LF wheel and push in the LF tires valve to release tire pressure until the horn chirps once, then do it to the RF, then RR, then the LR, the horn should now honk twice indicating the sensors had been learned, then refill all your tires to the proper tire pressure. That is if this method still works, I believe GM has deleted this method from the 2012 models. If it doesn't work then you'll need a Tire Pressure Monitor Sensor Activation Tool to reset the tire monitor.

I borrowed this from page 10-45 of the 2012 Impala Owner's Manual. I hope it's helpful for you!

"The TPMS sensor matching process is:
1. Set the parking brake.
2. Turn the ignition to ON/RUN with the engine off.
3. Press the Remote Keyless Entry (RKE) transmitter's Q and "buttons at the same time for approximately five seconds. The horn sounds twice to signal the
receiver is in relearn mode and the TIRE LEARNING ACTIVE message displays on the DIC screen.
4. Start with the driver side front tire.
5. Place the relearn tool against the tire sidewall, near the valve stem. Then press the button to activate the TPMS sensor. A horn chirp confirms that the sensor identification code has been matched to this tire and wheel position.
6. Proceed to the passenger side front tire, and repeat the procedure in Step 5.
7. Proceed to the passenger side rear tire, and repeat the procedure in Step 5.
8. Proceed to the driver side rear tire, and repeat the procedure in Step 5. The horn sounds two times to indicate the sensor identification code has been matched to the driver side rear tire, and the TPMS sensor matching process is no longer active. The TIRE LEARNING ACTIVE message on the DIC display screen goes off.
9. Turn the ignition to LOCK/OFF.
10. Set all four tires to the recommended air pressure level as indicated on the Tire
and Loading Information label."

Sarah (Assisting Katie), Chevrolet Customer Service

The Following User Says Thank You to ChevroletCustomerService For This Useful Post:

I borrowed this from page 10-45 of the 2012 Impala Owner's Manual. I hope it's helpful for you!

"The TPMS sensor matching process is...
4. Start with the driver side front tire.
5. Place the relearn tool against the tire sidewall, near the valve stem. Then press the button to activate the TPMS sensor. A horn chirp confirms that the sensor identification code has been matched to this tire and wheel position.
6. Proceed to the passenger side front tire, and repeat the procedure in Step 5.
7. Proceed to the passenger side rear tire, and repeat the procedure in Step 5.
8. Proceed to..."

Hey Sarah, this all assumes that the user has a TPMS reprogramming tool (something like the ATEQ VT15 for example). For 2012 and on, unless you have the tool, you will need to make a stop at a dealership or a garage to address the issue.

For the OP... I purchased the mentioned VT15, it works great, and is easy to use. After the 2nd time using it, it has already paid for itself in terms of savings over what I would have had to pay at the local GM dealership. :)

Edit: Just did a fast look on Amazon. Seems the one that I bought has gone up from $75 to $121... still not terrible. This one is tested to work with the Impala (well it works on MY 2013 Impala). They also have a cheaper unit, a VT5 for $75 that looks to do the similar. I cannot find this unit on the ATEQ site, so it may be a discontinued model. Buyer beware.